The present invention relates to a three-pole, gas-insulated switch arrangement.
A switch arrangement of this type is known, for example, from U.S. Pat. No. 4,788,392. Such switch arrangement has metallic encapsulation for each pole in the form of a cylindrical pole housing which is tightly connected at both ends to one plate common to all three poles, namely a cover plate at one end and a mechanism housing plate at the other end. The interrupter elements arranged in the pole housings are supported on these plates via insulators. The plates are fastened to a frame and bear the encapsulation. On the side facing away from the pole housings, the mechanism housing plate carries a mechanism housing, common to all poles, for a switch mechanism. The interior of the mechanism housing is connected to the interior of the three pole housings via openings in the mechanism housing plate. Switching rods coupled at one end to the switch mechanism and at the other end to the interrupter elements run through these openings. The switch mechanism is passed in gas-tightly manner through the wall of the mechanism housing and is connected to a drive common to all poles. The axes of the respective two bushings arranged on a pole housing extend in an axial plane of the pole housing. In order to keep the basic area required for the switch arrangement as small as possible, the axial plane of the middle pole extends vertically and the axial planes of the outer poles are inclined outwards with respect thereto.
The three poles of the known switch arrangement can be composed of identical parts. However, the encapsulation of all three poles forms a unit, which cannot be taken apart for transport without the possibility of air and moisture penetrating the interior of the encapsulation. If the switch arrangement is too bulky to be transported as a whole unit, it must be split into components. After assembly at the installation site, it is necessary for the interior of the encapsulation to be evacuated and dried again, which entails a considerable outlay.